The present invention relates to a dismantling device for dismantling a fuel injector, in particular a high-pressure direct injector, from a mounting bore in a cylinder head of an internal combustion engine. Fuel is injected directly into the combustion chamber of the internal combustion engine through this high-pressure direct injector.
German Published Patent Application No. 197 05 990 describes a dismantling device, which has a jacket body at least partially surrounding the fuel injector, can be used for dismantling a direct injecting fuel injector. At the time of assembly, the jacket body is already inserted into the mounting bore in the cylinder head together with the fuel injector. A first collar section provided on a first end of the jacket body can be connected in a non-positive manner to a mounting section of the fuel injector, which accommodates the first collar section. On a second end of the jacket body opposite the first end, there is a second collar section which presents an engagement face for a tool. A disadvantage of this dismantling device is that the connection of the dismantling device to the fuel injector is not optimized, and the force induction through the tool acting on the dismantling device can be improved. Another disadvantage is that the dismantling device must be mounted on the fuel injector before assembly and cannot be attached subsequently, e.g., when repair or replacement is required.
U.S. Pat. No. 4,561,159 describes a dismantling device for a diesel injection nozzle. An end area of the fuel injector opposite the spray orifice can be inserted at the side into a slit in the dismantling device. The dismantling device is not inserted into the mounting bore of the cylinder head and it does not remain in the mounting bore when assembled. The dismantling device described in U.S. Pat. No. 4,561,159 is instead a tool extension, which is attached to the fuel injector before dismantling the fuel injector. However, connecting the dismantling device to the fuel injector here is a relatively complicated process.
The dismantling device according to the present invention has the advantage that the dismantling device can be mounted on the fuel injector with relatively little effort, so that handling is greatly simplified. With the device according to the present invention, the fuel injector can be inserted at the side into the engagement section with little force because of the sickle-shaped, tapered design of the contact face. With the device according to claim 2, the engagement sections, which are designed to be narrow, may be snapped onto the fuel injector with a spring action. The dismantling device acts in an area relatively close to the spray section of the fuel injector, so that no axial dismantling force acts on the fuel injector. Therefore, parts that have a lower load capacity, in particular plastic injection-molded parts, can be used in the inlet section of the fuel injector.
If, as in the device according to the present invention, at least two narrow engagement sections are provided, separated from one another by recesses, it is advantageous if flattened areas or recesses are provided on the engagement sections, thereby weakening the flexural rigidity of the engagement sections. Therefore, the fuel injector can be inserted into the dismantling device with a lower force.
With the device according to the present invention, it is advantageous if a tubular section which completely surrounds the fuel injector is provided following the engagement section(s). This tubular section improves the stability of the dismantling device. Furthermore, it is possible to provide engagement elements for engaging a dismantling tool, such as elements in the form of boreholes passing through the tubular section. A tong-like tool, for example, can be inserted into these bores, so that the dismantling device can be gripped easily by this tong-like tool.
From the standpoint of the manufacturing technology, it may be advantageous for the dismantling device to be composed of multiple partial bodies. It may be advantageous for the partial bodies to have fastening elements on the tubular section, engaging in recesses on the adjacent partial bodies.
The dismantling device may be manufactured by rolling steel plate, for example. However, it is also possible to produce the dismantling device from a fiberglass-reinforced plastic by a plastic injection-molding method, for example.